CVE-2021-20091

The web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 do not properly sanitize user input. An authenticated remote attacker could leverage this vulnerability to alter device configuration, potentially gaining remote code execution.

Published: 2021-04-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20091 is rated High Risk (67.9/100): CVSS High severity, with high exploitation likelihood (EPSS 84.70%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20091

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-25 86.76% 84.70% -2.07%
2 2026-02-12 85.99% 86.76% +0.77%
3 2025-12-29 — 85.99% —

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20091

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2021-20091

Affected software / configurations for CVE-2021-20091

Vendor Product Version Raw CPE
buffalo wsr-2533dhpl2-bk_firmware <= 1.02 cpe:2.3:o:buffalo:wsr-2533dhpl2-bk_firmware:*:*:*:*:*:*:*:*
buffalo wsr-2533dhp3-bk_firmware <= 1.24 cpe:2.3:o:buffalo:wsr-2533dhp3-bk_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-20091

cvelogic Threat Intelligence